Hezbollah will make "the mistake of its life" if it starts a war with Israel, Prime Minister Benjamin Netanyahu said Sunday, as tensions rose on the Israel-Lebanon border.

His remarks came during a visit as the Israeli leader visited troops near Israel's northern border with Lebanon where increasing artillery exchanges have heightened fears of a new front opening as Israel battles Hamas in Gaza.

Israel's defence ministry on Sunday ordered the evacuation of another 14 communities near the border, adding to dozens that have already been told to evacuate.

The United States warned Iran or its allies against any "escalation" in the wake of Israel's war with Hamas, two top US officials said Sunday, hours after the Pentagon moved to step up military readiness in the region.

With tensions mounting, Washington also announced Sunday it had ordered non-emergency staff to leave its embassy in Iraq.

"We are concerned at the possibility of Iranian proxies escalating their attacks against our own personnel, our own people," Secretary of State Antony Blinken said on CBS News. "We expect there is a likelihood of escalation."

With the Israel-Hamas conflict unleashing furious emotions, American universities have struggled to walk an almost impossibly narrow line: satisfying the demands of rich donors that they more clearly support Israel, while also respecting protesters' rights of free expression.

Several wealthy Americans have threatened to withdraw their financial support from prestigious private schools like the Ivy League's Harvard University in Massachusetts, or the University of Pennsylvania, known as UPenn.

Police in London say nearly 100,000 people marched in the British capital in an event organised by pro-Palestinian groups, one of several such protests across Europe.

Demonstrators held signs reading "Freedom for Palestine", "Stop Bombing Gaza" and "End Israeli Apartheid". Many waved Palestinian flags and some chanted "5, 6, 7, 8, Israel is a terrorist state" and "Free Palestine".

Since shock Hamas attacks on Israel on October 7, which left 1,400 dead, Israel has launched devastating air and ground bombardments of Gaza. The Hamas authorities say 4,385 people have died.

A suicide drone hit an airbase in Iraq hosting US troops on Saturday, Iraqi security sources said, but the Pentagon said it could not confirm that such an attack took place.

Armed factions close to Iran have threatened to attack US interests in Iraq over Washington's support for Israel since Hamas militants killed more than 1,400 people in a shock cross-border attack from Gaza on October 7.

Israel's retaliatory bombardment of Gaza has killed more than 4,300 people, according to its Hamas-controlled health ministry.

Two weeks after Kibbutz Beeri lost 10 percent of its population in the bloody Hamas attack, Israeli soldiers are stationed within sight, primed for a looming ground invasion of Gaza.

The small community -- traumatised by the bloodshed, grieving its dead and fearful for friends taken hostage -- has become a symbol of the horrors Israel suffered in the October 7 onslaught.

Residents say some of the Hamas militants' guns still lie amid the rubble of Beeri, where one third of houses were destroyed and the survivors are wracked by doubts about the future.

Casualties were reported along the Israel-Lebanon border Saturday as the army traded fire with the Iran-backed militant group Hezbollah amid fears of a new front opening as Israel battles Hamas.

In south Lebanon, Hezbollah said four of its fighters were killed. Palestinian militant group Islamic Jihad said one of its fighters was also killed.

In northern Israel, a strike in the Margaliot area of the border wounded two Thai farm workers, Israel's Magen David Adom emergency medical service said.

Shocked by images of dead children in Gaza, Mustafa al-Sayyid quickly whisked his family to the closest shelter when Israeli strikes began near his village in southern Lebanon this week.

"What we are seeing on television -- the massacres happening in Gaza, the children -- it cuts your heart to pieces," said the 53-year-old from Beit Lif, barely six kilometres (3.7 miles) from the Israeli border.

"If I wasn't afraid this would happen to us, I wouldn't have left my home," said Sayyid, who has two wives and 11 children, around half of whom are under 10.

Omar Ashur became a refugee during the "Nakba" or "catastrophe" experienced by Palestinians following Israel's creation 75 years ago and now fears the ongoing bombardment of Gaza will again force him into exile.

A retired general from the Palestinian Authority security forces, 83-year-old Ashur lives in Al-Zahra in central Gaza where Israeli missiles flattened an area of more than 20 buildings late on Thursday.

Residents had been warned to flee before the strikes, but many of them raced into the street with no idea of where to go.

Boasting good relations with both Western governments and Hamas, the emirate of Qatar has emerged as the key power in efforts to release the hostages seized by the Palestinian militant group from Israel even as other states show readiness to help.

French President Emmanuel Macron on Friday lauded the key role played by Qatar in the release by Hamas of two American hostages held since its attack against Israel on October 7, adding he was confident of further releases.